Band-gap reference circuits are widely used for providing substantially constant reference voltages in various analog and integrated circuit devices. In many applications, band-gap reference circuits are configured to generate constant reference voltages over an intended temperature range and/or despite some variations in the power supply voltage.
A characteristic of a band-gap reference circuit is its start-up phase, during which a voltage at an output of the band-gap reference circuit changes from a standby level in a standby state to a stable reference voltage level in an operating state. Generally, a start-up circuit is provided and enabled for starting-up the band-gap reference circuit during the start-up phase. After the start-up phase, i.e., when the voltage at the output of the band-gap reference circuit has settled at the stable reference voltage level, the start-up circuit is disabled.